ref: 9d8b51969987fa5e4c5fa58f3e7d3bfb76bf6b1c
dir: /silk/silk_decode_parameters.c/
/***********************************************************************
Copyright (c) 2006-2011, Skype Limited. All rights reserved.
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modification, (subject to the limitations in the disclaimer below)
are permitted provided that the following conditions are met:
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this list of conditions and the following disclaimer.
- Redistributions in binary form must reproduce the above copyright
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documentation and/or other materials provided with the distribution.
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this software without specific prior written permission.
NO EXPRESS OR IMPLIED LICENSES TO ANY PARTY'S PATENT RIGHTS ARE GRANTED
BY THIS LICENSE. THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
CONTRIBUTORS ''AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING,
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COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
***********************************************************************/
#include "silk_main.h"
/* Decode parameters from payload */
void silk_decode_parameters(
silk_decoder_state *psDec, /* I/O State */
silk_decoder_control *psDecCtrl /* I/O Decoder control */
)
{
opus_int i, k, Ix;
opus_int16 pNLSF_Q15[ MAX_LPC_ORDER ], pNLSF0_Q15[ MAX_LPC_ORDER ];
const opus_int8 *cbk_ptr_Q7;
/* Dequant Gains */
silk_gains_dequant( psDecCtrl->Gains_Q16, psDec->indices.GainsIndices,
&psDec->LastGainIndex, psDec->nFramesDecoded, psDec->nb_subfr );
/****************/
/* Decode NLSFs */
/****************/
silk_NLSF_decode( pNLSF_Q15, psDec->indices.NLSFIndices, psDec->psNLSF_CB );
/* Convert NLSF parameters to AR prediction filter coefficients */
silk_NLSF2A( psDecCtrl->PredCoef_Q12[ 1 ], pNLSF_Q15, psDec->LPC_order );
/* If just reset, e.g., because internal Fs changed, do not allow interpolation */
/* improves the case of packet loss in the first frame after a switch */
if( psDec->first_frame_after_reset == 1 ) {
psDec->indices.NLSFInterpCoef_Q2 = 4;
}
if( psDec->indices.NLSFInterpCoef_Q2 < 4 ) {
/* Calculation of the interpolated NLSF0 vector from the interpolation factor, */
/* the previous NLSF1, and the current NLSF1 */
for( i = 0; i < psDec->LPC_order; i++ ) {
pNLSF0_Q15[ i ] = psDec->prevNLSF_Q15[ i ] + SKP_RSHIFT( SKP_MUL( psDec->indices.NLSFInterpCoef_Q2,
pNLSF_Q15[ i ] - psDec->prevNLSF_Q15[ i ] ), 2 );
}
/* Convert NLSF parameters to AR prediction filter coefficients */
silk_NLSF2A( psDecCtrl->PredCoef_Q12[ 0 ], pNLSF0_Q15, psDec->LPC_order );
} else {
/* Copy LPC coefficients for first half from second half */
SKP_memcpy( psDecCtrl->PredCoef_Q12[ 0 ], psDecCtrl->PredCoef_Q12[ 1 ],
psDec->LPC_order * sizeof( opus_int16 ) );
}
SKP_memcpy( psDec->prevNLSF_Q15, pNLSF_Q15, psDec->LPC_order * sizeof( opus_int16 ) );
/* After a packet loss do BWE of LPC coefs */
if( psDec->lossCnt ) {
silk_bwexpander( psDecCtrl->PredCoef_Q12[ 0 ], psDec->LPC_order, BWE_AFTER_LOSS_Q16 );
silk_bwexpander( psDecCtrl->PredCoef_Q12[ 1 ], psDec->LPC_order, BWE_AFTER_LOSS_Q16 );
}
if( psDec->indices.signalType == TYPE_VOICED ) {
/*********************/
/* Decode pitch lags */
/*********************/
/* Decode pitch values */
silk_decode_pitch( psDec->indices.lagIndex, psDec->indices.contourIndex, psDecCtrl->pitchL, psDec->fs_kHz, psDec->nb_subfr );
/* Decode Codebook Index */
cbk_ptr_Q7 = silk_LTP_vq_ptrs_Q7[ psDec->indices.PERIndex ]; /* set pointer to start of codebook */
for( k = 0; k < psDec->nb_subfr; k++ ) {
Ix = psDec->indices.LTPIndex[ k ];
for( i = 0; i < LTP_ORDER; i++ ) {
psDecCtrl->LTPCoef_Q14[ k * LTP_ORDER + i ] = SKP_LSHIFT( cbk_ptr_Q7[ Ix * LTP_ORDER + i ], 7 );
}
}
/**********************/
/* Decode LTP scaling */
/**********************/
Ix = psDec->indices.LTP_scaleIndex;
psDecCtrl->LTP_scale_Q14 = silk_LTPScales_table_Q14[ Ix ];
} else {
SKP_memset( psDecCtrl->pitchL, 0, psDec->nb_subfr * sizeof( opus_int ) );
SKP_memset( psDecCtrl->LTPCoef_Q14, 0, LTP_ORDER * psDec->nb_subfr * sizeof( opus_int16 ) );
psDec->indices.PERIndex = 0;
psDecCtrl->LTP_scale_Q14 = 0;
}
}